Staged Hybrid Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula.

There is a growing body of literature expanding the indication of endovascular aneurysm repair, from prophylactic treatment of aneurysms to other indications such as ruptured and complicated ruptured abdominal aneurysms. Concomitant aortocaval fistula is rare, and reports of open and endovascular repair exist. We report a unique hybrid approach to a case of a ruptured abdominal aortic aneurysm with aortocaval fistula, repaired primarily via endovascular approach in a hybrid, two-staged fashion. Representative images are presented in addition to a short review of this pathology.

HIV protease inhibitor exposure predicts cerebral small vessel disease.

OBJECTIVE: HIV-associated neurocognitive disorders (HANDs) remain prevalent in patients who receive HAART and may be associated with cumulative exposure to antiretroviral medications and other factors. We proposed that chronic toxic effects of antiretroviral drugs could contribute to cerebral small vessel disease (CSVD), which might be one of the key underpinnings of HAND. DESIGN: Clinicopathological cross-sectional study of HIV-infected adults in the California NeuroAIDS Tissue Network. METHODS: We employed multivariable logistic regression methods to determine associations between HAART exposure (protease inhibitor-based, nonprotease inhibitor-based, or no HAART) and CSVD occurrence (standard histopathology: moderate/severe, mild, or absent). We also associated HAND (relative to normal cognition) with CSVD, HIV-related neuropathologic changes, older age at death (≥50 years), sex, or hepatitis C virus infection. RESULTS: We found that both mild and moderate/severe CSVD were associated with protease inhibitor-based HAART exposure after adjusting for diabetes mellitus [odds ratio (OR) 2.8 (95% confidence interval, CI 1.03-7.9) and 2.6 (95% CI 1.03-6.7), respectively, n = 134]. Moderate/severe CSVD was associated with diabetes after adjusting for HAART exposure [OR 7.4 (95% CI 1.6-70.7), n = 134]. Notably, HAND was associated with mild CSVD [OR 4.8 (95% CI 1.1-21.2), n = 63], which remained statistically significant after adjusting for vessel mineralization, HIV encephalitis, microglial nodular lesions, white matter lesions, or older age. CONCLUSION: Protease inhibitor-based HAART exposure may increase the risk of CSVD and thereby neurocognitive impairment in HIV-infected adults. Apart from the possible direct toxicity to cerebral small vessels, protease inhibitor-based HAART may contribute indirectly to CSVD by inducing metabolic abnormalities.

Differential effect of gender on hepatic fat.

BACKGROUND: There are discrepant data on whether men or women have a higher risk for hepatic steatosis. OBJECTIVE: To examine the influence of gender on hepatic adiposity in teenagers and young adults. MATERIALS AND METHODS: We measured subcutaneous abdominal fat (SAF), intra-abdominal fat (IAF) and hepatic tissue density (a surrogate measure of hepatic fat) using CT in 505 healthy teenagers and young adults (254 males, 251 females; ages 15-22.9 years). RESULTS: Overall, compared to men, women had higher values of SAF (P < 0.0001) but similar measures of IAF and liver tissue density (P = 0.09 and 0.92, respectively). However, when compared to overweight/obese men, overweight/obese women had strikingly similar IAF values (P = 0.85) but lower hepatic fat (P = 0.009). Multiple regression analyses indicated that, after adjusting for age and SAF, IAF independently predicted hepatic density in males (P < 0.0001) but not in females (P = 0.36). Hepatic fat increased with body mass in males from lean to overweight and obese (P < 0.0001) but not in females (P > 0.05). CONCLUSION: When compared to overweight and obese young women, overweight and obese young men are at greater risk for hepatic steatosis, independent of IAF.

Differential computed tomographic attenuation of metabolically active and inactive adipose tissues: preliminary findings.

This study investigates differences in computed tomography Hounsfield units between metabolically active (brown fat) and inactive adipose tissues (white fat) due to variations in their densities. Positron emission and computed tomographic data from 101 pediatric and adolescent patients were analyzed. Regions of metabolically active and inactive adipose tissues were identified, and standard uptake values and Hounsfield units were measured. Hounsfield units of active brown fat were more positive (P < 0.001) than inactive fat (-62.4 ± 5.3 vs -86.7 ± 7.0) and the difference was observed in both males and females.

Functional brown adipose tissue is related to muscle volume in children and adolescents.

OBJECTIVE: We examined whether the depiction of brown adipose tissue (BAT) with positron emission tomography/computed tomography (PET/CT) in pediatric patients is associated with anthropometric measures. STUDY DESIGN: We determined measures of body mass, adiposity, and musculature in 71 children and adolescents who underwent PET/CT examinations and compared patients with and without BAT. We used regression analyses to assess the relation between BAT and anthropometric measures. RESULTS: A total of 30 patients (42%) had BAT depicted on PET/CT, 10 of 26 girls (38%) and 20 of 45 boys (44%). Compared with patients without functional BAT, patients with BAT had significantly greater neck musculature (1880 ± 908 cm(3) versus 1299 ± 806 cm(3); P = .028 for boys and 1295 ± 586 cm(3) versus 854 ± 392 cm(3); P = .030 for girls) and gluteus musculature (1359 ± 373 cm(3) versus 1061 ± 500 cm(3); P = .032 for boys and 1138 ± 425 cm(3) versus 827 ± 297 cm(3); P = .038 for girls), but no differences in age, body mass index, or measures of subcutaneous fat. With logistic regression analyses, neck and pelvic musculature predicted the presence of BAT independently of age, sex, body size, and season of scan (P = .018 and .009, respectively). CONCLUSION: Pediatric patients with visualized BAT on PET/CT examinations had significantly greater muscle volume than patients with no visualized BAT.

Bone marrow fat is inversely related to cortical bone in young and old subjects.

OBJECTIVE: Recent studies suggest a close local link between bone marrow adiposity and endosteal bone formation. Using magnetic resonance imaging, we examined whether the relation between the amount of marrow fat and cortical bone is present at multiple sites along the diaphyses of the long bones of young and old males and females. DESIGN: The relations between values for cortical bone area and percent marrow fat in each 5-mm section along the midthird of both femoral shafts were determined using magnetic resonance imaging in eight healthy young (aged <25 yr), and nine healthy old (aged >55 yr) men and women. RESULTS: Strong inverse correlations were observed between values for cortical bone area and percent marrow fat along the shafts of all 34 femurs; r values between -0.54 to -0.97; all P values = 0.01-0.0001. The strength of this local association was comparable in the young and the elderly and in males and females. CONCLUSION: Our results underscore the strength of the local connections between bone and marrow adiposity. Increasing our understanding of the mechanism for this association could lead to better diagnosis and treatment approaches for osteoporosis.

Effect of gender on intra-abdominal fat in teenagers and young adults.

BACKGROUND: Adult men accumulate greater intra-abdominal fat (IAF) than adult women, a difference closely related to gender differences in cardiometabolic disease risk in the elderly. However, the time when this gender difference appears is a matter of controversy. OBJECTIVE: We examine the influence of gender on IAF deposition in lean, overweight and obese teenagers and young adults. MATERIALS AND METHODS: We measured subcutaneous abdominal fat (SAF) and IAF in 505 healthy sexually mature teenagers and young adults (254 males, 251 females; 15-22 years) using a single CT scan at the level of the umbilicus. RESULTS: Regardless of body size, young females had greater SAF values than young males. Although lean females had higher IAF values than lean males (13.7 ± 7.8 vs. 11.2 ± 5.4; P = 0.001), overweight and obese females and males had strikingly similar IAF values (23.4 ± 11.1 vs. 23.1 ± 9.5; P = 0.88 and 36.5 ± 20.4 vs. 38.8 ± 13.2; P = 0.59, respectively). In contrast, the ratio of IAF/SAF was greater in males than females, except in the very obese. Multiple regression analysis indicated that while gender was a strong predictor of SAF in lean and overweight subjects (P's < 0.0001), it did not influence IAF after adjusting for height and weight (P = 0.35 and 0.65, respectively) in overweight and obese subjects. CONCLUSION: Overweight and obese young women have similar absolute amounts of IAF as young men.